Mounting fixture for assembling a plural-stage axial compressor



Nov. 10, 1970 w. SPRENGER 3,538,579

MOUNTING FIXTURE FOR YASSEMBLING A I PLURAL-STAGE AXIAL COMPRESSOR FiledJan. 24, 1968 3 Sheets-Sheet 1 In venlor:

Wolrer Sprenger ATTORNEYS Nov. 10, 1970 w. SPREN GER 3,538,579

I MOUNTING FIXTURE FOR ASSEMBLING A PLURAL-STAGE AXIAL COMPRESSOR FiledJan. 24,. 1968 3 Sheets-Sheet 2 Fly-5' In venlor:

Walter Sprenger J AAALI Nov. 10, 1970 MOUNTING FIXTURE FOR ASSEMBLING APLURAL-STAGE AXIAL COMPRESSOR Filed Jan. 24, 1968 L1,55- Q 2 g I 1 3% wA 3 5 s4 QQMQ M a f! M W i 6 60 o QQ \K" 0 QR Q Q? /54 W.SPRENGER3,538,579

SSheets-Sheet 3 In yen/0r:

ATTORNEYS United States Patent 3,538,579 MOUNTING FIXTURE FOR ASSEMBLINGA PLURAL-STAGE AXIAL COMPRESSOR Walter Sprenger, Zurich, Switzerland,assignor to Sulzer Brothers Limited, Winterthur, Switzerland, a Swisscompany Filed Jan. 24, 1968, Ser. No. 700,191 Claims priority,application Switzerland, Feb. 10, 1967, 2,021/ 67 Int. Cl. B23p 19/00,15/04; B23q 17/00 US. Cl. 29-200 3 Claims ABSTRACT OF THE DISCLOSURE Amounting fixture for assembly of a plural stage axial compressor inwhich a blade carrier divided into plural parts along an axial plane andprovided with a plurality of variable pitch blades is to be assembled toa pitch adjusting sheath, likewise divided into plural parts along anaxial plane, with pins on adjusting levers of the blades bein engaged ingrooves on the inside of the sheath. The fixture comprises a ringdemountable along a diameter into two parts and having two plane,parallel and coaxial annular surfaces, one for support of one bladecarrier part and the other for support of one sheath part, and twocylindrical surfaces coaxial with each other and with those annularsurfaces, one for centering of the blade carrier part and the other forcentering of the sheath part.

BACKGROUND OF THE INVENTION Field of the invention The present inventionpertains to fixture for assembling a plural-stage axial compressor inwhich a blade carrier of annular shape, divided into plural parts longan axial plane and supporting a plurality of rotable guide blades, iscoupled to an adjusting sheath of annular shape for the blades, whichsheath is similarly divided into plural parts along an axial plane orplanes, the pitch adjusting levers of the blades being provided withpegs or pins which are inserted into circular grooves distributedlengthwise of the inner circumference of the sheath.

In plural-stage axial compressors whose guide blades are disposed on ablade carrier and are adjusted in pitch by means of an axially movablesheath, the assembly of the blade carrier to the sheath is difficult andtime consuming since the pitch adjusting levers of the individual bladesmust all be inserted into circular grooves of the sheath. The fixtureaccording to the invention makes it possible to simplify the assembly ofthese parts. In accordance with the invention, one half of the bladecarrier and one half of the sheath are first supported opposite eachother on different diameters of the mounting ring but with their axescoaxial and vertical. These two halves are each of approximatelysemi-cylindrical shape, and will for convenience hereinafter sometimesbe referred to as shells. Thereafter, the adjusting levers of successiveaxial rows of the guide blades are positioned opposite the correspondinggrooves. The cranks or pins of the pitch adjusting levers for each axialrow of blades are then inserted into the grooves of the sheath byrelative rotation of the two shells with respect to each other abouttheir common axis, and finally the two shells are temporarily fastenedtogether by suitable means for insertion into the compressor housing.

Advantageously, one of the two halves or shells may be fixed to themounting ring while the other is movable with respect thereto, it beingadvantageous to rotate the sheath half about the blade carrier half.

3,538,579 Patented Nov. 10, 1970 The mounting ring of the invention issplit along a diameter into two detachable half rings but which whenfastened together form a ring possessing an inner annular support orbearing surface for the blade carrier and a circular centering surfaceby means of which the blade carrier is centered in the mounting ring. Italso includes an exterior annular suport surface for support of thesheath, concentric to the inner support surface, and a flange by meansof which the adjusting sheath is centered in the mounting ring. At leastone of the two support surfaces takes the form of a race and may beprovided with rollers.

In order to facilitate laying down of the two shells after assemblytogether with their axes vertical, one of the two halves of the splitmounting ring may be provided with a straight edge on its exterior.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be furtherdescribed in terms of a non-limitative example of the practice of themethod thereof and in terms of a non-limitative exemplary embodiment ofthe apparatus thereof and by reference to the accompanying drawings, inwhich:

FIG. 1 illustrates the support of the adjustable pitch guide blades inthe blade carrier, FIG. 1 taking the form of a fragmentary section alonga plane perpendicular to the axis of the machine;

FIGS. 2 and 3 are respectively plan and side elevational views of themounting or assembly ring of the invention, FIG. 3 being taken in thedirection indicated by the arrow A in FIG. 2 and FIG 3 moreover beingshown partly in section along the section line III-III of FIG. 2;

FIG. 4 shows at an enlarged scale the portion of FIG. 3 within the dashline box B in FIG. 3;

FIG. 5 is a view partly in section and partly plan of a suspension ringfor the blade carrier, ai'fixed thereto at the end of the blade carrieropposite the mounting ring of FIGS. 2 and 3;

FIG. 6 is a section taken along the line VI-VI of FIG. 5"

FIGS. 7 and 8 are plan and side elevational views, FIG. I

8 being taken in the direction indicated by the arrow K in FIG. 7, ofone means for temporarily fastening to each other a blade carrier halfand a sheath half assembled to gether, preliminary to insertion thereofinto the compressor; and

FIG. 9 is a fragmentary perspective view of a plural stage axialcompressor in which the assembly of one blade carrier half and of onesheath half is nearly completed.

In FIG. 1, reference character 3 identifies the annular streamingchannel provided between the guide blade carrier I and the rotor II ofthe axial compressor. The blade carrier is made up of two substantiallysemi-cylindrical halves or shells, one of which is identified atreference character 1 in FIG. 9. The guide blades 4 of adjustable pitchextend into this channel. One of these blades is illustrated atreference character 4. It is suported in a bore 5 of the carrier I andis provided with an O-ring disposed in a circular groove in order toseal the flow channel 3 off from the exterior. The O-ring simultaneouslyserves to protect the bearing of the blade 4 from fouling.

A sleeve 9 is disposed in the bore 5, supported at a shoulder 7 of thebore and fastened to the carrier 1 by screws not shown. Between theshoulder 7 of the bore 5 and the sleeve 9 there is inserted a washer 6which can vary in thickness from blade to blade. Its function is topermit control of the depth to which the sleeve '9 penetrates into thebore 5 and hence of the depth to which the blade 4 penetrates into thespace 3, and thereby of the approach of the blade tip to the rotor II.

An axial bearing ring 8 together with bushings 10 and 11 and a spacingring 12 are inserted into the sleeve 9.

The blade 4 is rotatably supported in the bushings and 11 at itscylindrical shaft 16. A cover 14 is supported on the sleeve 9 by meansof a further axial bearing ring 13, this cover being fastened to thesleeve 9 by means of screw 15. By means of the cover 14 and the screws15, the rings 8 and 13 and the bushings 10 and 11 and spacer 12 arefastened to the sleeve 9.

Rotation of the blade 4 for variation of pitch is effected by means ofthe adjusting lever 17 which is supported on a reduced extension 18 ofthe shaft 16 and which is held thereon by means of a nut 19. The nut islocked by means of a locking wafer 20. At its other end the adjustinglever 17 is provided with a crank pin 21 held in position by means of alocking pin 22. A slide 24 is rotatably engaged about pin 21 with aspacing washer 23 between the slide and the lever. The slide 24 fitsinto a corresponding groove 50 of the adjustment sheath, as illustratedin FIG. 9.

The mounting ring of the invention is illustrated in FIGS. 2, 3 and 4.It comprises two half rings 25a and 25b which can be fastened to eachother to make up a ring generally indicated at 25, for example by meansof screws, at flange-like extensions 27 and 28. Each half ring may becast integrally or made up of a number of parts welded together. Thehalf rings 25a and 25b possess together an inner plane annular supportsurface 29 for the blade carrier shell 1, spaced from the cylindricalcentering surface 30 by means of which the blade carrier shell 1 iscentered on the mounting ring 25 in the assembly process.

The outer plane annular support surface 31, which is radially outwardlydisposed with respect to the inner surface 29 and with respect to thecentering surface 30, serves to support one of the two halves or shells60 of the adjustment sheath, as shown in FIG. 9. The surfaces 29 and 31are parallel and coaxial. As is more particularly illustrated in FIG. 4,the surface 31 has cut therein a circular groove 32 concentrictherewith. Bearing rollers 34 supported on pins 33 are distributedaround this groove, as illustrated in FIG. 2, and the sheath shell 60rests thereon. The rollers 34 facilitate shift of the shell 60 Withrespect to the blade carrier shell 1. At its outer limit the supportsurface 31 is provided with a flange 35 having a cylindrical innersurface 35a coaxial with the cylindrical surface 30 and with the planesurfaces 29 and 31, by means of which the sheath shell 60 is held incoaxial position in the mounting ring 25 and with respect to the bladecarrier 1.

In order to facilitate laying down into horizontal position of theshells 1 and 60 after their assembly into interengaging relationshipwhile vertical, the half ring 25b is provided at its exterior with astraight edge or foot 36. The other half ring 25a is provided on itsexterior with studs 26, as indicated in FIG. 9, by means of which themounting ring 25 can be handled and transported.

The extension 36 additionally serves to permit disposition horizontally,before assembly into the housing of the compressor, of the halves of theblade carrier and sleeve assembled together in accordance with theinvention.

A second positioning or support foot, at the other end of the bladecarrier 1, is formed by the supporting and adjusting half-ring 37illustrated in FIGS. 5 and 6. This ring, which may also be cast, isprovided with bores 38 through which it may be fastened to the bladecarrier shell 1 by means of bolts, not shown. The ring 37 additionallyincludes at the exterior thereof an abutment or supporting surface 40,reinforced by means of three ribs 39. The abutment edge 40 cooperateswith the extension 36 on the ring 25 to support the assembly inhorizontal position. Additionally, eyes 42 are provided at two flatextensions 41 on the exterior of the ring 37. Through these eyes, thering 37 and consequently the shells 1 and 60 fastened thereto may besuspended for insertion into the housing of the compressor. The eyes 42may however be replaced with studs similar to the studs 26 alreadyreferred to. Additionally, the ring 37 is provided to the left and tothe right of the middle rib 39 with bores 43 through which the upperhalf of the adjustment sheath can, after assembly to its half of theblade carrier, be clamped between the rings 25b and 37 by means ofscrews, not shown, for insertion into the compressor housing. The phraseupper half here is used to refer to the fact that preferably the firstpair of shells (one shell 1 and one shell 60) are assembled together andthen inserted into the compressor housing with their concave sidesupward, in the lower half of the cavity provided for the blade carrierand sheath in the compressor housing. The second pair ofsemi-cylindrical shells, including one shell 1 and one shell 60, maythus be referred to as the upper shells.

The fastening elements 44 shown in FIGS. 7 and 8, by means of which thefirst or lower sheath half or shell 60 and the appurtenant half 1 of theblade carrier are temporarily fastened to each other for insertion intothe compressor housing, comprise in substance a substantiallyrectangular base plate 49 provided with four holes 45. Through theseholes the elements 44 are fastened to the blade carrier half 1 by meansof threaded studs 46 and similarly to the adjustment sheath half 60,near the axial ends thereof (i.e., at the top and bottom thereof in FIG.9). This is done after the blade carrier half and sheath half have beenassembled together and rotated about their common axis so that theirlimiting axial planes substantially coincide. In this position, two ofthe holes 45 of each plate 44 accommodate studs 46 of the blade carrierhalf, and two accommodate bolts which thread into bores 54 of the sheathhalf. In this way, the lower halves of the blade carrier 1 and sheath 60are fastened with respect to each other before they are assembled intothe housing.

In addition, sleeves or Washers 47 are afiixed to each plate 49 aboutthe two holes 45 provided for studs 46 from the blade carrier half 1.These sleeves are fitted to the length of the threaded bolts 46- whichsubsequently serve to fasten together the two halves of the bladecarrier. That is, the sleeves 47 are of such length that nuts run downover the threaded parts of studs 46 will serve to hold the plates 49against the parting plane surface of the blade carrier half 1. Inaddition, each of the plates 49 is provided with a hook 48 at the freeside thereof, i.e., on the same side as the sleeves 47. The hooks 48serve to permit the fastening of cords by means of which the bladecarrier and sheath halves may be suspended during assembly. The hooks 48are so disposed on the plates 49 that the cords contact each other abovethe center of gravity of the combined halves 1 and 60 At this contactpoint the assembled shells 1 and 60 are suspended for transport. Thefastening elements 44 may be cast or made of separate elements weldedtogether.

The adjustment sheath, which is axially split just as is the bladecarrier 1 and which as indicated in FIG. 9 may moreover in largemachines be divided perpendicularly to its axis as well, is made up ofthin sheets or plates reinforced at their ends by means of a ring 53 andby means of flanges 51 and 52 along the parting surfaces thereof. Bores54 are provided in the flanges 51 which receive fastening bolts uponassembly of the two semi-cyclindrical halves together. In addition,guide rails 55 are fastened to the flanges 51 in order to permit thesheath to move axially of the compressor so as to effect changes inpitch of the guide blades. Motion of the sheath is effected by means ofa device such as a servo-motor through a linkage, not shown, whichengages the blocks 56 fastened to the flanges 51.

The groove-bearing rings 50' are welded or otherwise fastened to theinner surface of the sheath. These grooves receive the pins 21 andslides 24 of the pitch changing levers 17 illustrated in FIG. 1. Inaddition, two collars 57 are fastened to the inner surface of the sheath60.

These collars can rest against corresponding surfaces 58 on the outsideof the blade carrier. The collars 57 and the cooperating surfaces 58serve to support the sheath half 60 and carrier half 1 with respect toeach other during assembly so as to prevent stressing of the pins 21 onthe levers 17. During operation of the completed compressor a smallclearance of the order of 2 mm. exists between the collars 57 and thesurfaces 58.

The blade carrier halves are provided with a number of threaded bores 59at their upper reinforced edges. These bores receive screws forfastening of the supporting and adjusting ring 37 of FIG. 5.

In the embodiment illustrated, assembly of the blade carrier andadjusting sheath is carried out according to the invention in thefollowing manner.

One blade carrier half 1 is first so fastened to the semiring 25b thatwhen the assembly thereof with one sheath half is later set upright, theblade carrier half will rest on the supporting surface 29 and becentered at the surface 30. Then, the mounting ring 25 is completed byscrewing on the second half 25a and the blade supporting half 1 is setupright, with its axis vertical, with the aid of the ring 25. One half60 of adjustment sheath is then set on the rollers 34 of the other halfring 25a and centered against the surface 35a. In the next step theadjustment levers 17 of the blades 4 in one vertical row C (FIG. 9) areso disposed that the slides 24 thereof stand opposite the correspondinggrooves 50 of the sheath, as is illustrated for the rows F and G in FIG.9.

The sheath half 60, which can be readily moved on the rollers 34, isthen rotated in the direction of the arrow H in FIG. 9 past the firstrow C of blades 4. The rows D, E, etc. are then successively set up withinsertion of the slides 24 of those rows successively into the grooves50 upon further rotation of the sheath half 60. Insertion successivelyof the vertical rows of blade adjustment levers into the grooves 50continues until the rows F and G are thus inserted. Thereupon the ring37 is fastened to the blade carrier half 1 by means of screws enteringthe tapped holes 59.

Although the process hereinabove described, for assembly of the lowerhalf of the blade carrier 1 to the lower half of the sheath 60 is thesame as that employed in assembling together their upper halves,'thefastening of the two halves together occurs differently in the two casesin view of the difference in conditions obtaining in the two cases.

In the case of the lower halves, the fastening takes place by means ofthe elements 44 illustrated in FIGS. 7 and 8. As hereinabove alreadybriefly stated, the fastening elements 44 are affixed to the planes 51of the flanges on the sheath half 60 and to the corresponding surfacesalong the parting plane of the blade carrier half 1, these surfacesbeing coplanar with the planes 51 when the lower half of the sheath andlower half of the blade carrier have been fully assembled together. Thehalf ring 25a is then removed. The lower half assembly, comprising asemicylindrical half of the blade carrier and a semi-cylindrical half ofthe sheath, is then set down on the supports 36 and of the half rings25b and 37, this operation being carried out with the aid of a suitablehandling fixture which connects to the ring 37.

After the fixture is connected to the hooks 48 of the fastening means44, the two half rings 25b and 37 are removed and the lower half of theassembly comprising a blade carrier half 1 and a sheath half 60 isinserted into the compressor housing. The temporary fastening plates 44may then be removed.

The other two halves, one of the blade carrier and the other of thesheath, are then assembled together in substantially the same way, toform the upper half of the complete assembly which when completed willcomprise an annular blade carrier inside an annular sheath. Sincehowever the fastening elements 44 would prevent setting of the upperhalf of the assembly onto the lower half already inserted into thecompressor housing, aifixation of the upper half of the sheath '60 tothe upper half of the carrier 1 is effected by means of the support ring37, fastened at 3 8 to the upper half of the carrier whereby the upperhalf of the sheath 60 is clamped between the rings 25b and 37 by meansof screws passing through the threaded bores 43 (FIG. 5). Afterloosening of the semiring 25a, the assembled upper half of the bladecarrier 1 and of the sheath 60 are then set onto the lower half of theassembly in the compressor housing, with the aid of the fixture whichconnects to the eyes 42 of ring 37 and to the studs 26 of the half ring25b, whereafter the half rings 25b and 37 may be removed. The two halves1 of the blade carrier are then assembled together by means of screws 46and nuts, not shown. To fasten the nuts and screws together the upperhalf of the sheath 60 is provided with slotted holes, not shown, throughwhich a. wrench can be passed. Finally the two halves of the sheath 60are then fastened together by screws, not shown, passing through thebores 54.

While the present invention has been described herein in terms of 'apresently preferred embodiment of the apparatus thereof and in terms ofthe presently preferred practice of the method thereof, the inventionitself is not limited thereto but, rather, comprises all modificationson and departures from that embodiment and preferred practice properlyfalling within the spirit and scope of the appended claims.

T claim:

1. A mounting fixture for assembling a plural stage axial compressor inwhich an annular blade carrier divided into plural parts along an axialplane fits within an annular blade pitch adjusting sheath likewisedivided into plural parts along an axial plane, said fixture comprisinga ring demountable into a plurality of parts, said ring having aradially inner annular plane surface for support of one of said carrierparts, a first cylindrical surface for centering of said one carrierpart, a radially outer annular plane surface for support of one of saidsheath parts, and a second cylindrical surface for centering said onesheath part.

2. A mounting fixture according to claim- 1 including rollers disposedadjacent at least one of said plane annular surfaces.

.3. A mounting fixture according to claim 1 including a straightextension on at least one of the plurality of parts of the ring thereof.

References Cited UNITED 'STATES PATENTS 1,580,426 4/1926 Farnam 29--2003,286,335 11/1966 Di Pietra 29-200 THOMAS H. EAGER, Primary Examiner US.Cl. X.-R.

